By Claudia López Lloreda For a neuroscientist, the opportunity to record single neurons in people doesn’t knock every day. It is so rare, in fact, that after 14 years of waiting by the door, Florian Mormann says he has recruited just 110 participants—all with intractable epilepsy. All participants had electrodes temporarily implanted in their brains to monitor their seizures. But the slow work to build this cohort is starting to pay off for Mormann, a group leader at the University of Bonn, and for other researchers taking a similar approach, according to a flurry of studies published in the past year. For instance, certain neurons selectively respond not only to particular scents but also to the words and images associated with them, Mormann and his colleagues reported in October. Other neurons help to encode stimuli, form memories and construct representations of the world, recent work from other teams reveals. Cortical neurons encode specific information about the phonetics of speech, two independent teams reported last year. Hippocampal cells contribute to working memory and map out time in novel ways, two other teams discovered last year, and some cells in the region encode information related to a person’s changing knowledge about the world, a study published in August found. These studies offer the chance to answer questions about human brain function that remain challenging to answer using animal models, says Ziv Williams, associate professor of neurosurgery at Harvard Medical School, who led one of the teams that worked on speech phonetics. “Concept cells,” he notes by way of example, such as those Mormann identified, or the “Jennifer Aniston” neurons famously described in a 2005 study, have proved elusive in the monkey brain. © 2025 Simons Foundation

Keyword: Attention; Learning & Memory
Link ID: 29709 - Posted: 03.19.2025

Nicola Davis Science correspondent Cat owners are being asked share their pet’s quirky traits and even post researchers their fur in an effort to shed light on how cats’ health and behaviour are influenced by their genetics. The scientists behind the project, Darwin’s Cats, are hoping to enrol 100,000 felines, from pedigrees to moggies, with the DNA of 5,000 cats expected to be sequenced in the next year. The team say the goal is to produce the world’s largest feline genetic database. “Unlike most existing databases, which tend to focus on specific breeds or veterinary applications, Darwin’s Cats is building a diverse, large-scale dataset that includes pet cats, strays and mixed breeds from all walks of life,” said Dr Elinor Karlsson, the chief scientist at the US nonprofit organisation Darwin’s Ark, director of the vertebrate genomics group at the Broad Institute of MIT and Harvard and associate professor at the UMass Chan medical school. “It’s important to note, this is an open data project, so we will share the data with other scientists as the dataset grows,” she added. The project follows on the heels of Darwin’s Dogs, a similar endeavour that has shed light on aspects of canine behaviour, disease and the genetic origins of modern breeds. Darwin’s Cats was launched in mid-2024 and already has more than 3,000 cats enrolled, although not all have submitted fur samples. Participants from all parts of the world are asked to complete a number of free surveys about their pet’s physical traits, behaviour, environment, and health. © 2025 Guardian News & Media Limited

Keyword: Genes & Behavior; Development of the Brain
Link ID: 29708 - Posted: 03.19.2025

By Gina Kolata Women’s brains are superior to men’s in at least in one respect — they age more slowly. And now, a group of researchers reports that they have found a gene in mice that rejuvenates female brains. Humans have the same gene. The discovery suggests a possible way to help both women and men avoid cognitive declines in advanced age. The study was published Wednesday in the journal Science Advances. The journal also published two other studies on women’s brains, one on the effect of hormone therapy on the brain and another on how age at the onset of menopause shapes the risk of getting Alzheimer’s disease. The evidence that women’s brains age more slowly than men’s seemed compelling. Researchers, looking at the way the brain uses blood sugar, had already found that the brains of aging women are years younger, in metabolic terms, than the brains of aging men. Other scientists, examining markings on DNA, found that female brains are a year or so younger than male brains. And careful cognitive studies of healthy older people found that women had better memories and cognitive function than men of the same age. Dr. Dena Dubal, a professor of neurology at the University of California, San Francisco, set out to understand why. “We really wanted to know what could underlie this female resilience,” Dr. Dubal said. So she and her colleagues focused on the one factor that differentiates females and males: the X chromosome. Females have two X chromosomes; males have one X and one Y chromosome. Early in pregnancy, one of the X chromosomes in females shuts down and its genes go nearly silent. But that silencing changes in aging, Dr. Dubal found. © 2025 The New York Times Company

Keyword: Alzheimers; Sexual Behavior
Link ID: 29704 - Posted: 03.12.2025

By Kelly Servick New York City—A recent meeting here on consciousness started from a relatively uncontroversial premise: A newly fertilized human egg isn’t conscious, and a preschooler is, so consciousness must emerge somewhere in between. But the gathering, sponsored by New York University (NYU), quickly veered into more unsettled territory. At the Infant Consciousness Conference from 28 February to 1 March, researchers explored when and how consciousness might arise, and how to find out. They also considered hints from recent brain imaging studies that the capacity for consciousness could emerge before birth, toward the end of gestation. “Fetal consciousness would have been a less central topic at a meeting like this a few years ago,” says Claudia Passos-Ferreira, a bioethicist at NYU who co-organized the gathering. The conversation has implications for how best to care for premature infants, she says, and intersects with thorny issues such as abortion. “Whatever you claim about this, there are some moral implications.” How to define consciousness is itself the subject of debate. “Each of us might have a slightly different definition,” neuroscientist Lorina Naci of Trinity College Dublin acknowledged at the meeting before describing how she views consciousness—as the capacity to have an experience or a subjective point of view. There’s also vigorous debate about where consciousness arises in the brain and what types of neural activity define it. That makes it hard to agree on specific markers of consciousness in beings—such as babies—that can’t talk about their experience. Further complicating the picture, the nature of consciousness could be different for infants than adults, researchers noted at the meeting. And it may emerge gradually versus all at once, on different timescales for different individuals.

Keyword: Consciousness; Development of the Brain
Link ID: 29703 - Posted: 03.12.2025

By Angie Voyles Askham Synaptic plasticity in the hippocampus involves both strengthening relevant connections and weakening irrelevant ones. That sapping of synaptic links, called long-term depression (LTD), can occur through two distinct routes: the activity of either NMDA receptors or metabotropic glutamate receptors (mGluRs). The mGluR-dependent form of LTD, required for immediate translation of mRNAs at the synapse, appears to go awry in fragile X syndrome, a genetic condition that stems from loss of the protein FMRP and is characterized by intellectual disability and often autism. Possibly as a result, mice that model fragile X exhibit altered protein synthesis regulation in the hippocampus, an increase in dendritic spines and overactive neurons. Treatments for fragile X that focus on dialing down the mGluR pathway and tamping down protein synthesis at the synapse have shown success in quelling those traits in mice, but they have repeatedly failed in human clinical trials. But the alternative pathway—via the NMDA receptor—may provide better results, according to a new study. Signaling through the NMDA receptor subunit GluN2B can also decrease spine density and alleviate fragile-X-linked traits in mice, the work shows. “You don’t have to modulate the protein synthesis directly,” says Lynn Raymond, professor of psychiatry and chair in neuroscience at the University of British Columbia, who was not involved in the work. Instead, activation of part of the GluN2B subunit can indirectly shift the balance of mRNAs that are translated at the synapse. “It’s just another piece of the puzzle, but I think it’s a very important piece,” she says. Whether this insight will advance fragile X treatments remains to be seen, says Wayne Sossin, professor of neurology and neurosurgery at Montreal Neurological Institute-Hospital, who was not involved in the study. Multiple groups have cured fragile-X-like traits in mice by altering what happens at the synapse, he says. “Altering translation in a number of ways seems to change the balance that is off when you lose FMRP. And it’s not really clear how specific that is for FMRP.” © 2025 Simons Foundation

Keyword: Development of the Brain; Learning & Memory
Link ID: 29700 - Posted: 03.12.2025

By Tim Vernimmen On a rainy day in July 2024, Tim Bliss and Terje Lømo are in the best of moods, chuckling and joking over brunch, occasionally pounding the table to make a point. They’re at Lømo’s house near Oslo, Norway, where they’ve met to write about the late neuroscientist Per Andersen, in whose lab they conducted groundbreaking experiments more than 50 years ago. The duo only ever wrote one research paper together, in 1973, but that work is now considered a turning point in the study of learning and memory. Published in the Journal of Physiology, it was the first demonstration that when a neuron — a cell that receives and sends signals throughout the nervous system — signals to another neuron frequently enough, the second neuron will later respond more strongly to new signals, not for just seconds or minutes, but for hours. It would take decades to fully understand the implications of their research, but Bliss and Lømo had discovered something momentous: a phenomenon called long-term potentiation, or LTP, which researchers now know is fundamental to the brain’s ability to learn and remember. Today, scientists agree that LTP plays a major role in the strengthening of neuronal connections, or synapses, that allow the brain to adjust in response to experience. And growing evidence suggests that LTP may also be crucially involved in a variety of problems, including memory deficits and pain disorders. Bliss and Lømo never wrote another research article together. In fact, they would soon stop working on LTP — Bliss for about a decade, Lømo for the rest of his life. Although the researchers knew they had discovered something important, at first the paper “didn’t make a big splash,” Bliss says. By the early 1970s, neuroscientist Eric Kandel had demonstrated that some simple forms of learning can be explained by chemical changes in synapses — at least in a species of sea slug. But scientists didn’t yet know if such findings applied to mammals, or if they could explain more complex and enduring types of learning, such as the formation of memories that may last for years.

Keyword: Learning & Memory
Link ID: 29694 - Posted: 03.05.2025

By Lola Butcher Last September, Eliezer Masliah, a prominent Alzheimer’s disease researcher, stepped away from his influential position at the National Institutes of Health after the organization, where he oversaw a $2.6 billion budget for neuroscience research, found falsified or fabricated images in his scientific articles. That same month, the Securities and Exchange Commission announced neuroscientist Lindsay Burns, her boss, and their company would pay more than $40 million to settle charges they had made misleading statements about research results from their clinical trial of a possible treatment for Alzheimer’s disease. Also in September: A $30 million clinical trial to study a stroke treatment developed by Berislav Zlokovic, a well-known Alzheimer’s expert, and his colleagues was canceled amid an investigation into whether he had manipulated images and data in research publications. Shortly thereafter, Zlokovic, director of the Zilkha Neurogenetic Institute at the University of Southern California medical school, was placed on indefinite administrative leave. Is there a pattern here? And, if there is, can neurology patients trust treatments that are based on published scientific research? That is what Charles Piller, an investigative reporter for Science magazine, examines in “Doctored: Fraud, Arrogance, and Tragedy in the Quest to Cure Alzheimer’s,” and his analysis is not comforting. As for the first question — is there a pattern? — Piller’s relentless reporting reveals that dozens of neuroscientists, including some of the most prominent in the world, appear to be responsible for inaccurate images in their published research. Those problematic images have prompted many of their articles to be retracted, corrected, or flagged as being “of concern” by the journals in which they were published.

Keyword: Alzheimers
Link ID: 29687 - Posted: 03.01.2025

By Ingrid Wickelgren After shuffling the cards in a standard 52-card deck, Alex Mullen, a three-time world memory champion, can memorize their order in under 20 seconds. As he flips though the cards, he takes a mental walk through a house. At each point in his journey — the mailbox, front door, staircase and so on — he attaches a card. To recall the cards, he relives the trip. This technique, called “method of loci” or “memory palace,” is effective because it mirrors the way the brain naturally constructs narrative memories: Mullen’s memory for the card order is built on the scaffold of a familiar journey. We all do something similar every day, as we use familiar sequences of events, such as the repeated steps that unfold during a meal at a restaurant or a trip through the airport, as a home for specific details — an exceptional appetizer or an object flagged at security. The general narrative makes the noteworthy features easier to recall later. “You are taking these details and connecting them to this prior knowledge,” said Christopher Baldassano (opens a new tab), a cognitive neuroscientist at Columbia University. “We think this is how you create your autobiographical memories.” Psychologists empirically introduced (opens a new tab) this theory some 50 years ago, but proof of such scaffolds in the brain was missing. Then, in 2018, Baldassano found it: neural fingerprints of narrative experience, derived from brain scans, that replay sequentially during standard life events. He believes that the brain builds a rich library of scripts for expected scenarios — restaurant or airport, business deal or marriage proposal — over a person’s lifetime. These standardized scripts, and departures from them, influence how and how well we remember specific instances of these event types, his lab has found. And recently, in a paper published in Current Biology in fall 2024, they showed that individuals can select a dominant script (opens a new tab) for a complex, real-world event — for example, while watching a marriage proposal in a restaurant, we might opt, subconsciously, for either a proposal or a restaurant script — which determines what details we remember. © 2025 Simons Foundation

Keyword: Learning & Memory; Attention
Link ID: 29685 - Posted: 02.26.2025

Jon Hamilton People who inherit one very rare gene mutation are virtually guaranteed to develop Alzheimer's before they turn 50. Except for Doug Whitney. "I'm 75 years old, and I think I'm functioning fairly well," says Whitney, who lives near Seattle. "I'm still not showing any of the symptoms of Alzheimer's." Now a team of scientists is trying to understand how Whitney's brain has defied his genetic destiny. "If we are able to learn what is causing the protection here, then we could translate that to therapeutic approaches and apply that to the more common forms of the disease," says Dr. Jorge Llibre-Guerra, an assistant professor of neurology at Washington University School of Medicine in St. Louis. One possibility is high levels of heat shock proteins found in Whitney's brain, the team reports in the journal Nature Medicine. There are hints that these proteins can prevent the spread of a toxic protein that is one of the hallmarks of Alzheimer's, Llibre-Guerra says. A genetic surprise Early-onset Alzheimer's is everywhere in Whitney's family. His mother and 11 of her 13 siblings all had the disease by about age 50. "None of them lasted past 60," Whitney says. Whitney's wife, Ione, saw this up close. "We went home for Thanksgiving, and his mom couldn't remember the pumpkin pie recipe," she says. "A year later when we went back, she was already wandering off and not finding her way back home." © 2025 npr

Keyword: Alzheimers; Genes & Behavior
Link ID: 29675 - Posted: 02.19.2025

By Michael S. Rosenwald In early February, Vishvaa Rajakumar, a 20-year-old Indian college student, won the Memory League World Championship, an online competition pitting people against one another with challenges like memorizing the order of 80 random numbers faster than most people can tie a shoelace. The renowned neuroscientist Eleanor Maguire, who died in January, studied mental athletes like Mr. Rajakumar and found that many of them used the ancient Roman “method of loci,” a memorization trick also known as the “memory palace.” The technique takes several forms, but it generally involves visualizing a large house and assigning memories to rooms. Mentally walking through the house fires up the hippocampus, the seahorse-shaped engine of memory deep in the brain that consumed Dr. Maguire’s career. We asked Mr. Rajakumar about his strategies of memorization. His answers, lightly edited and condensed for clarity, are below. Q. How do you prepare for the Memory League World Championship? Hydration is very important because it helps your brain. When you memorize things, you usually sub-vocalize, and it helps to have a clear throat. Let’s say you’re reading a book. You’re not reading it out loud, but you are vocalizing within yourself. If you don’t drink a lot of water, your speed will be a bit low. If you drink a lot of water, it will be more and more clear and you can read it faster. Q. What does your memory palace look like? Let’s say my first location is my room where I sleep. My second location is the kitchen. And the third location is my hall. The fourth location is my veranda. Another location is my bathroom. Let’s say I am memorizing a list of words. Let’s say 10 words. What I do is, I take a pair of words, make a story out of them and place them in a location. And I take the next two words. I make a story out of them. I place them in the second location. The memory palace will help you to remember the sequence. © 2025 The New York Times Company

Keyword: Learning & Memory; Attention
Link ID: 29673 - Posted: 02.15.2025

By Angie Voyles Askham Identifying what a particular neuromodulator does in the brain—let alone how such molecules interact—has vexed researchers for decades. Dopamine agonists increase reward-seeking, whereas serotonin agonists decrease it, for example, suggesting that the two neuromodulators act in opposition. And yet, neurons in the brain’s limbic regions release both chemicals in response to a reward (and also to a punishment), albeit on different timescales, electrophysiological recordings have revealed, pointing to a complementary relationship. This dual response suggests that the interplay between dopamine and serotonin may be important for learning. But no tools existed to simultaneously manipulate the neuromodulators and test their respective roles in a particular area of the brain—at least, not until now—says Robert Malenka, professor of psychiatry and behavioral sciences at Stanford University. As it turns out, serotonin and dopamine join forces in the nucleus accumbens during reinforcement learning, according to a new study Malenka led, yet they act in opposition: dopamine as a gas pedal and serotonin as a brake on signaling that a stimulus is rewarding. The mice he and his colleagues studied learned faster and performed more reliably when the team optogenetically pressed on the animals’ dopamine “gas” as they simultaneously eased off the serotonin “brake.” “It adds a very rich and beguiling picture of the interaction between dopamine and serotonin,” says Peter Dayan, director of computational neuroscience at the Max Planck Institute for Biological Cybernetics. In 2002, Dayan proposed a different framework for how dopamine and serotonin might work in opposition, but he was not involved in the new study. The new work “partially recapitulates” that 2002 proposal, Dayan adds, “but also poses many more questions.” © 2025 Simons Foundation

Keyword: Learning & Memory
Link ID: 29672 - Posted: 02.15.2025

By Michael S. Rosenwald Eleanor Maguire, a cognitive neuroscientist whose research on the human hippocampus — especially those belonging to London taxi drivers — transformed the understanding of memory, revealing that a key structure in the brain can be strengthened like a muscle, died on Jan. 4 in London. She was 54. Her death, at a hospice facility, was confirmed by Cathy Price, her colleague at the U.C.L. Queen Square Institute of Neurology. Dr. Maguire was diagnosed with spinal cancer in 2022 and had recently developed pneumonia. Working for 30 years in a small, tight-knit lab, Dr. Maguire obsessed over the hippocampus — a seahorse-shaped engine of memory deep in the brain — like a meticulous, relentless detective trying to solve a cold case. An early pioneer of using functional magnetic resonance imaging (f.M.R.I.) on living subjects, Dr. Maguire was able to look inside human brains as they processed information. Her studies revealed that the hippocampus can grow, and that memory is not a replay of the past but rather an active reconstructive process that shapes how people imagine the future. “She was absolutely one of the leading researchers of her generation in the world on memory,” Chris Frith, an emeritus professor of neuropsychology at University College London, said in an interview. “She changed our understanding of memory, and I think she also gave us important new ways of studying it.” In 1995, while she was a postdoctoral fellow in Dr. Frith’s lab, she was watching television one evening when she stumbled on “The Knowledge,” a quirky film about prospective London taxi drivers memorizing the city’s 25,000 streets to prepare for a three-year-long series of licensing tests. Dr. Maguire, who said she rarely drove because she feared never arriving at her destination, was mesmerized. “I am absolutely appalling at finding my way around,” she once told The Daily Telegraph. “I wondered, ‘How are some people so bloody good and I am so terrible?’” In the first of a series of studies, Dr. Maguire and her colleagues scanned the brains of taxi drivers while quizzing them about the shortest routes between various destinations in London. © 2025 The New York Times Company

Keyword: Learning & Memory
Link ID: 29671 - Posted: 02.15.2025

By Sara Reardon A man who seemed genetically destined to develop Alzheimer’s disease while still young has reached his mid-70s without any cognitive decline — in only the third recorded case of such resistance to the disease. The findings, published today in Nature Medicine1, raise questions about the role of the proteins that ravage the brain during the disease and the drugs that target them. Since 2011, a study called the Dominantly Inherited Alzheimer Network (DIAN) has been following a family in which many members have a mutation in a gene called PSEN2. The mutation causes the brain to produce versions of the amyloid protein that are prone to clumping into the sticky plaques thought to drive neurodegeneration. Family members with the mutation invariably develop Alzheimer’s at around age 50. Then, a 61-year-old man from this family showed up at the DIAN study’s clinic with full cognitive function, and the researchers were shocked to discover that he had the fateful PSEN2 mutation. The man’s mother had had the same mutation, as had 11 of her 13 siblings; all had developed dementia around age 50. The researchers were even more shocked when scans revealed that his brain looked like that of someone with Alzheimer’s. “His brain was full of amyloid,” says behavioural neurologist and study co-author Jorge Llibre-Guerra at Washington University in St. Louis, Missouri. What the man’s brain didn’t contain, however, were clusters of tau — another protein that forms tangled threads inside neurons. Positron emission tomography (PET) scans revealed that he had a small amount of abnormal tau and that it was only in the occipital lobe, a brain region involved in visual perception that is not usually affected in Alzheimer’s disease. © 2025 Springer Nature Limited

Keyword: Alzheimers; Genes & Behavior
Link ID: 29667 - Posted: 02.12.2025

By Felicity Nelson Mice immediately bolt for shelter when they see the looming shadow of a bird, just as humans jump when they see a spider. But these instinctive reactions, which are controlled by the brainstem, can be suppressed if animals learn that a scary stimulus is harmless. In Science today, neuroscientists reveal the precise regions of the brain that suppress fear responses in mice1 — a finding that might help scientists to develop strategies for treating post-traumatic stress disorder and anxiety in people. The study showed that two parts of the brain work together to learn to suppress fear. But, surprisingly, only one of these regions is involved in later recalling the learnt behaviour. “This is the first evidence of that mechanism,” says neuroscientist Pascal Carrive at the University of New South Wales in Sydney, Australia. In the study, an expanding dark circle was used to imitate a swooping bird, and caused naive mice to run to a shelter. To teach the mice that this looming stimulus was not dangerous, a barrier was added to prevent the animals from hiding. “I like their behavioural model,” says Christina Perry, a behavioural neuroscientist at Macquarie University in Sydney. “It’s very simple,” she adds. The mice “don’t get eaten, so they learn that this fake predator is not, in fact, a threat”. As the mice were learning to be bolder, the researchers switched specific types of neurons on or off using optogenetics — a well-established technique that allows neurons to be controlled with light. When researchers silenced the parts of the cerebral cortex that analyse visual stimuli (called the posterolateral higher visual areas), the mice did not learn to suppress fear and continued to try to escape from the fake bird — suggesting that this area of the brain is necessary for learning to suppress this fear reaction. © 2025 Springer Nature Limited

Keyword: Emotions; Stress
Link ID: 29664 - Posted: 02.08.2025

By Laura Hercher edited by Gary Stix It is impossible, of course, to identify the precise moment we first suspected the changes in my mother were something other than normal aging. In my own imperfect memory, what rises up is the first morning of a weeklong trip to Rome, when my mother woke up at 2 A.M., got dressed and went down for breakfast. A hotel employee found her wandering from room to room, looking for toast and coffee. She was jet-lagged, my brother and I told each other uneasily. It could happen to anyone. But weren’t there cues? Didn’t she notice the darkened lobby, the stillness, the clock? If we had known then, would it have helped? To date, no U.S. Food and Drug Administration–­approved therapy exists for asymptomatic people at risk of Alzheimer’s disease (AD). My mother was not a smoker, drank in moderation, read books, took classes, and spent that week in Italy soaking up everything the tour guide told her about Caravaggio and Bernini like she was prepping for a quiz. Five years passed after that trip before my mother received a diagnosis of dementia. Today, a simple blood test can detect changes in the brain that predict AD up to 15 years before the first symptoms emerge. For researchers, tools for early detection give a peek at the full spectrum of AD, pinpointing early seeds of pathology deep inside the brain. Cognitive decline—what we typically think of as the disease itself—is merely the illness’s denouement. “Dementia is a result. Dementia is a symptom,” explains Clifford R. Jack, Jr., a neuroradiologist at the Mayo Clinic in Rochester, Minn., and chair of the Alzheimer’s Association (AA) working group responsible for recent, controversial guidelines for the diagnosis of AD based on underlying biology, not clinical presentation. Scientific American is part of Springer Nature,

Keyword: Alzheimers
Link ID: 29657 - Posted: 02.05.2025

By Catherine Offord In scientists’ search to understand the causes of autism, a spotlight has fallen on maternal health during pregnancy. Based partly on association studies, researchers have proposed that conditions including obesity and depression during pregnancy could lead to autism in a child by affecting fetal neurodevelopment. But a study of more than 1 million Danish children and their families, published today in Nature Medicine, pushes back against this view. Researchers analyzed more than 200 health conditions that occurred in these children’s mothers before or during pregnancy. They conclude that many of the supposed links to a child’s autism diagnosis may not be causal, and instead reflect inherited genetic variants or environmental factors shared within families. “It’s a very comprehensive and well-done study,” says Håkan Karlsson, a neuroscientist at the Karolinska Institute who was not involved in the work. It suggests “conditions [pregnant people] suffered from during pregnancy are probably not the cause of autism in their kid.” The findings dovetail with a growing view in the field that shared genetics could explain a lot of the apparent connections between maternal health and autism, adds Drexel University epidemiologist Brian Lee. However, he and others caution the study doesn’t rule out that some conditions during pregnancy could have a causative role, nor does it identify factors that do influence the likelihood of autism. Previous research has linked conditions such as maternal obesity, psychiatric disorders, and pregnancy or birth complications to an increased likelihood of autism diagnoses in children. Such findings can lead some pregnant people to feel that “if they get this or that condition, their [child’s] chance of autism may increase,” says Magdalena Janecka, an epidemiologist at New York University’s Grossman School of Medicine and a co-author on the new paper. © 2025 American Association for the Advancement of Science.

Keyword: Autism
Link ID: 29652 - Posted: 02.01.2025

By Katharine Gammon Today more than 55 million people around the world have Alzheimer’s disease and other dementias, which ravage the minds of those who suffer from them and have devastating impacts on their family members. In spite of decades of research, the precise origins of these diseases continue to elude scientists, though numerous factors have been found to be associated with higher risk, including genetics and various lifestyle and environmental factors. Nautilus Members enjoy an ad-free experience. Log in or Join now . The quest has recently taken a turn to a newer model for studying the brain: brain organoids. These three-dimensional clumps of neuronal tissue derived from human stem cells have been used to study everything from epilepsy to the origins of consciousness. And now, researchers in Massachusetts are slamming them with miniature metal pistons to test out whether they can lend credence to a controversial hypothesis: that concussions might reactivate a common virus in the brain, increasing dementia risk. A decade of research suggests traumatic brain injury, whether from accidents or high-contact sports, is a standout risk factor for Alzheimer’s and other forms of neurodegenerative decline. Some estimates suggest that up to 10 percent of cases could be attributed to at least one prior head injury, but why is not fully understood. Separately, a growing body of research proposes that viral infection, including a common virus known as herpes simplex one, can also increase susceptibility to these diseases. But all three things—head trauma, viral infection, and dementia—have not been directly connected in experimental research, until now. One of the challenges in getting to the roots of dementia is that humans lead complex, messy lives. In the soup of risk factors—from high blood pressure to loneliness to genetic inheritance—it can be hard to filter out the most impactful forces that have contributed to the onset of any one dementia case. There are no ethical ways to test these questions on humans, of course, while using lab animals presents its own ethical and cost challenges. Animals are never a perfect match for humans anyway, and dementia-related findings in animals have so far not translated well to human patients. © 2025 NautilusNext Inc.,

Keyword: Alzheimers; Brain Injury/Concussion
Link ID: 29646 - Posted: 01.29.2025

By Yasemin Saplakoglu Imagine you’re on a first date, sipping a martini at a bar. You eat an olive and patiently listen to your date tell you about his job at a bank. Your brain is processing this scene, in part, by breaking it down into concepts. Bar. Date. Martini. Olive. Bank. Deep in your brain, neurons known as concept cells are firing. You might have concept cells that fire for martinis but not for olives. Or ones that fire for bars — perhaps even that specific bar, if you’ve been there before. The idea of a “bank” also has its own set of concept cells, maybe millions of them. And there, in that dimly lit bar, you’re starting to form concept cells for your date, whether you like him or not. Those cells will fire when something reminds you of him. Concept neurons fire for their concept no matter how it is presented: in real life or a photo, in text or speech, on television or in a podcast. “It’s more abstract, really different from what you’re seeing,” said Elizabeth Buffalo (opens a new tab), a neuroscientist at the University of Washington. For decades, neuroscientists mocked the idea that the brain could have such intense selectivity, down to the level of an individual neuron: How could there be one or more neurons for each of the seemingly countless concepts we engage with over a lifetime? “It’s inefficient. It’s not economic,” people broadly agreed, according to the neurobiologist Florian Mormann (opens a new tab) at the University of Bonn. But when researchers identified concept cells in the early 2000s, the laughter started to fade. Over the past 20 years, they have established that concept cells not only exist but are critical to the way the brain abstracts and stores information. New studies, including one recently published in Nature Communications, have suggested that they may be central to how we form and retrieve memory. © 2025 Simons Foundation

Keyword: Learning & Memory; Attention
Link ID: 29639 - Posted: 01.22.2025

By Holly Barker Previously unrecognized genetic changes on the X chromosome of autistic people could explain the higher prevalence of the condition among men and boys than among women and girls, according to two new studies. About 60 variants are more common in people with autism than in those without the condition, an analysis of roughly 15,000 X chromosomes revealed. Several of the variants are in Xp22.11, a region of the X chromosome linked to autism in boys and men. In the second study, the team pinpointed 27 autism-linked variants in DDX53, one of the genes in the vulnerable region that had not been tied to the condition in past research. Those findings could help explain why autism is diagnosed three to four times more often in boys than girls, according to the study investigators, led by Stephen Scherer, chief of research at SickKids Research Institute. Although that disparity is likely influenced by social factors—male-only studies could lead to autism being less recognizable in women and girls, and girls may be conditioned to mask their autism traits—there is also a clear biological component. The X chromosome plays an outsized role in brain development, and many genes on the chromosome are strongly linked to autism, previous studies have found. Still, the sex chromosomes have been mostly ignored in genetic searches of autism variants, says Aaron Besterman, associate clinical professor of psychiatry at the University of California, San Diego, who was not involved in the work. “It’s been a dirty little secret that for a long time the X chromosome has not been well interrogated from a genetics perspective,” he says. Sex chromosomes are often sidelined because of difficulties interpreting data, given that men possess half the number of X-linked genes as women. What’s more, random inactivation of X chromosomes makes it hard to tell how a single variant is expressed in female tissues. And the existence of pseudoautosomal regions—stretches of DNA that behave like regular chromosomes and escape inactivation—complicates matters further. © 2025 Simons Foundation

Keyword: Autism; Sexual Behavior
Link ID: 29638 - Posted: 01.22.2025

Rachael Elward Lauren Ford Severance, which imagines a world where a person’s work and personal lives are surgically separated, will soon return to Apple TV+ for a second season. While the concept of this gripping piece of science fiction is far-fetched, it touches on some interesting neuroscience. Can a person’s mind really be surgically split in two? Remarkably, “split-brain” patients have existed since the 1940s. To control epilepsy symptoms, these patients underwent a surgery to separate the left and right hemispheres. Similar surgeries still happen today. Later research on this type of surgery showed that the separated hemispheres of split-brain patients could process information independently. This raises the uncomfortable possibility that the procedure creates two separate minds living in one brain. In season one of Severance, Helly R (Britt Lower) experienced a conflict between her “innie” (the side of her mind that remembered her work life) and her “outie” (the side outside of work). Similarly, there is evidence of a conflict between the two hemispheres of real split-brain patients. When speaking with split-brain patients, you are usually communicating with the left hemisphere of the brain, which controls speech. However, some patients can communicate from their right hemisphere by writing, for example, or arranging Scrabble letters. A young patient was asked what job he would like in the future. His left hemisphere chose an office job making technical drawings. His right hemisphere, however, arranged letters to spell “automobile racer”. Split brain patients have also reported “alien hand syndrome”, where one of their hands is perceived to be moving of its own volition. These observations suggest that two separate conscious “people” may coexist in one brain and may have conflicting goals. In Severance, however, both the innie and the outie have access to speech. This is one indicator that the fictional “severance procedure” must involve a more complex separation of the brain’s networks. © 2010–2025, The Conversation US, Inc.

Keyword: Learning & Memory; Consciousness
Link ID: 29635 - Posted: 01.18.2025